Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Beyond the readOnly/openWorld/idempotent annotations, the description discloses the verdict taxonomy (pass, fail, unverified), the fallback path when judgment fails, and what is returned as evidence, including the paid-key screenshot caveat. This is exactly the kind of outcome and quota context an agent cannot get from the annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Four tight sentences, front-loaded with the action, then predicate semantics, then the fallback behavior, then verdict definitions. No filler and no restatement of the tool name or schema types.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description carries the return-value burden and does explain verdict meanings and the shape of returned evidence at a high level. The exact structure of the evidence payload is still only sketched, which is the one remaining gap for a five-parameter tool.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is already 100%, so the baseline is 3, but the description adds a meaningful distinction the schema does not: must_contain, must_not_contain and expect_status are 'checked exactly' while 'expectation' requires judgment. That tells the agent how determinism differs across parameters, which affects how results should be trusted.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description gives a concrete verb and object: 'Check a claim about a live page,' and then names the exact predicate parameters it evaluates. It is clearly a page-assertion tool rather than a plain fetch, which separates it from 'read'/'see', but it never explicitly contrasts itself with those siblings.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Usage is implied by explaining what each check type does, so an agent can infer when a deterministic containment check is preferable to a free-text expectation. However, there is no explicit statement of when to call 'verify' versus 'read' or 'perceive', and no stated preconditions such as requiring the page to be reachable first.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.